My sunfire signature stereo amp is arriving today or tomorrow. Looking at the picture the seller sent (see attached) it looks like I'll need to get a power extension and there appears to be no earth pin on the plug. Also checking a pdf of the manual for a slightly later model (the one with an on/off switch) this also seems to have no earth. Is this correct - and if so, why so? Always thought high current equipment with metal cases should run an earth wire. Thanks.

Yes, the extra ground was a thing to pass ul listings, it was and is as bob put it, not required, but it made ul labs happy. If you take the cover off, look at the wires, and i am sure you can convert if that is important.

Your AC supply wire appears to be non-stock / modified. Your amp is an IEC Protection Class I electronic device, meaning that it is a metal boxed appliance that is single-insulated and designed to have it's chassis in continuity with electrical earth. Be advised that the recommendation that no chassis-earth connection is required would only be true in the event that you amp was a IEC Class II double-insulated electronic device. It isn't.

I would replace the AC supply wire with a 3-conductor mains cable, attaching the earth/ground wire directly to a dedicated bolt on the chassis using a lockwasher.

Don't let anyone tell you that earth grounding a metal chassis is unnecessary. Earth grounding is a safety feature to protect you against electrocution in the event that something should go seriously awry in the amp.

Professional equipment often has three blade plugs. This is because it is frequently moved and abused, uses balanced interconnects which mitigate ground loops, and is sometimes connected to unknown power sources. It's also exposed to wet, incapacitated, barefoot, immature, public crowds. Hmmm, sounds like the gear at my house... Anyhow, here's what Peavey has to say on why three conductors are a good idea:

I guess if the amp was made with no earth, I'll probably leave it that way. In this apartment - there are no earths on the wall sockets anyway except for the kitchen. I'm moving - which is why I asked (and I'll have an earth put in if there's not one there!). Thanks for the replies.

surdo wrote:I guess if the amp was made with no earth, I'll probably leave it that way. In this apartment - there are no earths on the wall sockets anyway except for the kitchen. I'm moving - which is why I asked (and I'll have an earth put in if there's not one there!). Thanks for the replies.

Again i tell you , the man that built the amp did not see it as required, so keep that in mind. If it is something that makes you more comfortable, by all means do it.

As i got to know bob a little, one thing that stuck with me is his observation of how people have a tendency to substitute their think for his with the best of intensions. He said people do it all the time, and i see that he is far more patient than i would have been.... So i submit bob p, i take my hat off to your wisdom.,

It's evident that you have no formal training, that you lack any technical expertise in this area, and that you're not a certified design engineer. The result is that because of your lack of technical expertise in the field, you have to rely upon the opinion of an expert to find the correct answer. You're also a Bob Carver groupie, so you revere Bob as God. Because he is your God, you must revere him as the final authority on everything. It's what Groupies do.

Now I have no problem with anyone being a Bob Carver Groupie. I have a lot of respect for him. But there does come a problem when people who lack the knowledge to draw the proper conclusion on their own, due to lack of formal education, are forced to rely upon the opinion of "experts" because they have no other option available to them. In their quest for the right answer they don't have the ability to determine which expert is the right expert, so choosing an expert becomes a popularity contest when someone who is not formally educated has to decide which expert to trust. Unfortunately, in that circumstance the amount of end-user sophistication ends up being focused on which expert should be trusted, rather than critically reviewing the quality of the answers presented.

Bob's decision may have been OK when the amp was manufactured, but that design no longer meets current electrical safety standards in any developed country. Today he would not be allowed to sell such a Class I device without earth grounding in either the USA or the EU. That renders his outdated advice as moot.

It's OK to put your life at risk by relying upon outdated hearsay recommendations. I have no problem when someone who lacks formal education makes the best decision that he can make, using the resources available to him, to make a decision that effects his own personal case. But it does become a problem when someone who is ignorant of the commonly accepted engineering practices chooses to rely upon outdated advice, and parrot it, and then pontificate as if he were some sort of expert, thereby placing somebody else's life at risk. That's just irresponsible. What's even worse is that when the accepted safety standards are referenced, your response is to mock the advice of a competent design engineer, when you don't have a clue what you're talking about.

Class I devices need a dedicated ground wire. Period. That is the standard. In the 21st Century a device that lacks such safety features cannot be sold in the USA, Canada or the EU. I'm not sure about the regulations in Brazil, but like most countries, they may choose to follow the CE standard. What troubles me about this thread is that the OP came up with a question, already knowing the right answer, and an ignoramus has convinced him to abandon it.

It's evident that you have no formal training, that you lack any technical expertise in this area, and that you're not a certified design engineer. The result is that because of your lack of technical expertise in the field, you have to rely upon the opinion of an expert to find the correct answer. You're also a Bob Carver groupie, so you revere Bob as God. Because he is your God, you must revere him as the final authority on everything. It's what Groupies do.

Now I have no problem with anyone being a Bob Carver Groupie. I have a lot of respect for him. But there does come a problem when people who lack the knowledge to draw the proper conclusion on their own, due to lack of formal education, are forced to rely upon the opinion of "experts" because they have no other option available to them. In their quest for the right answer they don't have the ability to determine which expert is the right expert, so choosing an expert becomes a popularity contest when someone who is not formally educated has to decide which expert to trust. Unfortunately, in that circumstance the amount of end-user sophistication ends up being focused on which expert should be trusted, rather than critically reviewing the quality of the answers presented.

Bob's decision may have been OK when the amp was manufactured, but that design no longer meets current electrical safety standards in any developed country. Today he would not be allowed to sell such a Class I device without earth grounding in either the USA or the EU. That renders his outdated advice as moot.

It's OK to put your life at risk by relying upon outdated hearsay recommendations. I have no problem when someone who lacks formal education makes the best decision that he can make, using the resources available to him, to make a decision that effects his own personal case. But it does become a problem when someone who is ignorant of the commonly accepted engineering practices chooses to rely upon outdated advice, and parrot it, and then pontificate as if he were some sort of expert, thereby placing somebody else's life at risk. That's just irresponsible. What's even worse is that when the accepted safety standards are referenced, your response is to mock the advice of a competent design engineer, when you don't have a clue what you're talking about.

Class I devices need a dedicated ground wire. Period. That is the standard. In the 21st Century a device that lacks such safety features cannot be sold in the USA, Canada or the EU. I'm not sure about the regulations in Brazil, but like most countries, they may choose to follow the CE standard. What troubles me about this thread is that the OP came up with a question, already knowing the right answer, and an ignoramus has convinced him to abandon it.

It's evident that you have no formal training, that you lack any technical expertise in this area, and that you're not a certified design engineer. The result is that because of your lack of technical expertise in the field, you have to rely upon the opinion of an expert to find the correct answer. You're also a Bob Carver groupie, so you revere Bob as God. Because he is your God, you must revere him as the final authority on everything. It's what Groupies do.

Now I have no problem with anyone being a Bob Carver Groupie. I have a lot of respect for him. But there does come a problem when people who lack the knowledge to draw the proper conclusion on their own, due to lack of formal education, are forced to rely upon the opinion of "experts" because they have no other option available to them. In their quest for the right answer they don't have the ability to determine which expert is the right expert, so choosing an expert becomes a popularity contest when someone who is not formally educated has to decide which expert to trust. Unfortunately, in that circumstance the amount of end-user sophistication ends up being focused on which expert should be trusted, rather than critically reviewing the quality of the answers presented.

You do have a problem with it, above is a indication why....

Bob's decision may have been OK when the amp was manufactured, but that design no longer meets current electrical safety standards in any developed country. Today he would not be allowed to sell such a Class I device without earth grounding in either the USA or the EU. That renders his outdated advice as moot.

That is what i said above, it is extra protection , but not anything more than a addition ground wire to back up the already grounded wire.

It's OK to put your life at risk by relying upon outdated hearsay recommendations. I have no problem when someone who lacks formal education makes the best decision that he can make, using the resources available to him, to make a decision that effects his own personal case. But it does become a problem when someone who is ignorant of the commonly accepted engineering practices chooses to rely upon outdated advice, and parrot it, and then pontificate as if he were some sort of expert, thereby placing somebody else's life at risk. That's just irresponsible. What's even worse is that when the accepted safety standards are referenced, your response is to mock the advice of a competent design engineer, when you don't have a clue what you're talking about.

Yes, bobs old, good thing math has not changed. Although i am not from Missouri, i still look for the show me proof! For decades this way works well, and then a better way is shown. Does that mean i should add airbag safety to my seventies elcamino? Because that is the standard now?

Class I devices need a dedicated ground wire. Period. That is the standard. In the 21st Century a device that lacks such safety features cannot be sold in the USA, Canada or the EU. I'm not sure about the regulations in Brazil, but like most countries, they may choose to follow the CE standard. What troubles me about this thread is that the OP came up with a question, already knowing the right answer, and an ignoramus has convinced him to abandon it.

Yes, well said. Regulations. Because why? Its better, thanks for that.

Yes, you are correct, i have no formal training, and look forward to the education i am sure you will provide me and others.

TNRabbit wrote:So....something that was safe & an industry standard in the past is now "putting your life in danger?"

Call me pompous if you want, but you're not even close to being on target here, Gary.

Your statement doesn't accurately describe the situation because you are looking at a modified unit, not a stock unit as it came from the factory. And the modification was botched so that it's not in compliance with electrical safety standards. The unit, as it sits, presents a fire risk.

The device in question bears a logo mark which states that it had EU safety certification at the time it was manufactured. (Notice the CE symbol on the back panel.) CE certification of a Class I device requires a ground wire. The device in the photo doesn't have the same type of AC power cord that it had when it was manufactured with CE certification because some third party modified the device in the field to render the device compliant with Brazil-type power outlets. Unfortunately, the modder botched the conversion by not using IEC cable Type-N.

A Type-C plug is only allowed to be used on a device that is fused at 2.5 amps or less. I looked for the current rating for the fuse on that Sunfire amp, but I couldn't find the right manual and I couldn't read it in the photo. Based on all of the other Carver gear I've seen, I'm going to assume that that Sunfire amp has a higher current rating than the 2.5 amp safety limit of a Type-C plug.

As a result of the field modification the device no longer meets the CE safety certification that is implied by the logo on the back panel. As a result of the modification the unit in question is no longer compliant with the industry standard for safety at the time that it was manufactured. That is the problem. That botched power cord modification removed a safeguard that was designed into the device when it was manufactured. That botched power cord modification puts someone's life in danger for TWO reasons:

A) The power cable does not have an adequate current rating for the device, which causes a fire hazard under normal operating conditions;B) The unit has no earth ground, which causes an electrocution hazard.

If that were my amp, I'd re-wire it with a Type-N power connector and I'd earth ground the chassis as described previously.